%0 Journal Article %A St Leger, Raymond J. %A Cooper, Richard M. %A Charnley, A. Keith %T Cuticle-degrading Enzymes of Entomopathogenic Fungi: Regulation of Production of Chitinolytic Enzymes %D 1986 %J Microbiology, %V 132 %N 6 %P 1509-1517 %@ 1465-2080 %R https://doi.org/10.1099/00221287-132-6-1509 %I Microbiology Society, %X Synthesis of chitinase and chitosanase by the entomopathogenic fungus Metarhizium anisopliae is regulated by products of chitin and chitosan degradation through an inducer-repressor mechanism. Slow-feeding with sugars or alanine (about 20 μg ml−1 h−1) in a carbon deficient medium to prevent catabolite repression (restricted cultures) demonstrated that the most effective inducers of chitinase and chitosanase were the principal monomeric constituents of chitin (N-acetylglucosamine) and chitosan (glucosamine) respectively. Increasing the rate of release of N-acetylglucosamine decreased chitinase synthesis by about 87% while causing a sevenfold increase in growth. In batch cultures high chitinase activities were present only in chitin-containing medium. There was a negative correlation between accessibility and amount of chitin substrates, levels of free N-acetylglucosamine in culture fluids and chitinase production. Addition of carbohydrates, lipid or proteins to chitin-grown cultures repressed chitinase production. Basal levels of chitinase were produced in non-inducing media. Production of chitobiase (N-acetylglucosaminidase) was enhanced from high basal levels by amino sugars, but was less inducible and less susceptible to catabolite repression than chitinase. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-132-6-1509